This invention relates to apparatus and method for producing shaped paper products, such as coffee filters, by mechanically shaping paper sheet stock into the desired form and then steam heat setting the form to maintain its desired shape.
As explained in more detail hereinafter, it has been known to produce shaped paper products by forming paper sheet stock into the desired shape and heating the shaped product in order to maintain the desired form upon removal from the apparatus, the heating being accomplished by air and electric resistance heaters. However, such method and apparatus have numerous problems, especially fire hazards.
Steam has been used in the formation of paper and related products. See U.S. Pat. Nos. 1,431,922 and 2,149,507.